Jacquard machine

ABSTRACT

Each lifter ( 2 ) has a displacement member ( 4 ) which can be connected to at least one directable thread ( 18 ) and which has two spring arms ( 28   a   , 28   b ) that can be coupled to lifter blades ( 34   a   , 34   b ) which move up and down. The lifter blades are not attached to the spring arms ( 28   a   , 28   b ) in the starting position of the latter. In the lower shed position (T), the spring arms ( 28 a,  28 b) can be displaced into position for coupling with the lifter blades ( 34   a   , 34   b ) using an actuator ( 40 ). The displacement member ( 4 ) can be locked in the upper shed position using the same actuator ( 40 ). To improve the jacquard machine, the switching member ( 38 ) is positioned at the end of a spring tongue ( 44 ) that is aligned in the direction of displacement and is fixed to the displacement member ( 4, 4   a ) outside the spring arms ( 28   a   , 28   b ). The actuator ( 40, 40   a ) is located laterally outside the spring arms ( 28   a,    28   b ) in such a way that it acts transversely in relation to the latter.

TECHNICAL FIELD

The invention relates to a jacquard machine which has lifters which canbe connected to threads to be controlled and which can be coupled in aform-fitting manner to oppositely ascending and descending liftingknives as a function of control signals from an electronic controldevice, each lifter having a displacement member which, on the one hand,can be connected to at least one thread to be controlled and, on theother hand, carries two spring arms which in the basic position are freeof the lifting knives and in the lower shed position can be brought intoa coupling position for the lifting knives by means of an actuator, andin the upper shed position the displacement member being interlockableby means of the actuator.

PRIOR ART

A jacquard machine of the type initially mentioned is known, forexample, from U.S. Pat. No. 5,743,308. In such, a jacquard machine, theactuator, designed as an electromagnet, is arranged with a switch memberbetween the spring arms of a two-armed lifter, this being a greatdisadvantage for the small form of construction which is necessary.Moreover, access is difficult to the components located between thespring arms for maintenance and setting work. Another disadvantage isthat the spring arms are provided with outward-pointing locking noseswhich cooperate with fixed locking knives. In one example, the lockingnoses are prestressed interlockingly against the locking knives by thespring force of the spring arms and have to be released from the lockingknives by the spring arms being bent in by means of the actuator. In afurther example, the locking noses are arranged on tongue springsconnected to the lifter and have to be brought into engagement with thelocking knives by being spread outward by means of the actuator. Apartfrom the fact that the double arrangement of the locking noses andlocking knives leads to a complicated construction, the resilientarrangement of the locking noses causes vibrations which are detrimentalto the functioning of the jacquard machine.

PRESENTATION OF THE INVENTION

The object of the invention is to improve a jacquard machine of the typeinitially mentioned.

The set object is achieved by means of a jacquard machine wherein theswitch member is arranged at the end of a spring tongue oriented in thedirection of displacement and fastened to the displacement memberoutside the spring arms, the actuator being arranged laterally outsidethe spring arms and so as to act transversely thereto.

Since the switch member is arranged at the end of a spring tongueoriented in the direction of displacement and fastened to thedisplacement member outside the spring arms, the actuator being arrangedlaterally outside the spring arms and so as to act transversely thereto,the space between the spring arms is free of components, thus resultingin a highly space-saving and slender form of construction of thelifters. Since both the switch member and the actuator are locatedoutside the lifter, they are accessible in a simple way for setting andmaintenance work.

Advantageous refinements of the invention include the provision of atleast one rigid catch arranged on the displacement member for detentionin the upper shed position and with which the actuator directlycooperates. Further refinements include providing the displacementmember with at least two catches arranged at different heights,preferably catch recesses for the actuator, providing the actuator aspart of an electromagnet, providing the actuator as part of apiezoelectric element, providing the lifter of the jacquard machine withrun-on surfaces which, in the upper shed position, keep the spring armsspread in the coupling position, providing the lifter an assignedpreferably settable stop determining the lower shed position, providingthe displacement member with a back part which is equipped with a guideprofile and which is mounted displaceably in a guide in the machinestand, the hack part being on the side facing away from the actuator,and wherein the lifting knives are designed to execute an overmovementin the upper shed position and/or the lower shed position.

A particularly advantageous jacquard machine is obtained when at leastone rigid catch, with which the actuator cooperates directly, isarranged on the displacement member for detaining the lifter in theupper shed position. This design simplifies construction, since there isonly one catch which, moreover, is accessible from the outside. Therigid catch also prevents undesirable vibrations and resonances, withthe result that not only is the useful life of the jacquard machinelengthened, but also higher performances are possible.

So that the height of the shed can be set, a refinement of providing thedisplacement member with at least two catches arranged at differentheights, preferably catch recesses for the actuator is advantageous,since each locking point for interlocking the displacement member withthe actuator corresponds to a defined height of the shed.

There are various possibilities for designing the actuator. First, forexample, it may be designed as an electromagnet. The design wherein theactuator is designed as a piezoelectric element is more advantageous.

For coupling the spring arms in the upper shed position, there arevarious possibilities, the design having run-on surfaces for the springarms in the upper shed position being particularly advantageous andsimple.

A development of the jacquard machine wherein the lifter is assigned apreferably settable stop is particularly expedient, since settable stopsdetermining the lower shed position allow a further setting of the shed.

A displacement member requires, in the machine stand, a guide for whichthere are various design possibilities. A particularly simple andspace-saving solution is one wherein the displacement member has a backpart on the side facing away from the actuator, the back part beingequipped with a guide profile and which is mounted displaceably in aguide in the machine stand.

According to one preferred aspect of the invention, the lifting knivesare designed in such a way that they execute some overmovement in theupper shed position and/or lower shed position, with the result that theelements to be switched are free of form-fitting engagement and/or oftensile forces and switching is made possible or at least easier.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the jacquard machine according to the inventionare described in more detail below with reference to the drawings inwhich:

FIG. 1 shows a lifter in the lower shed position and in the basicposition of the spring arms in a diagrammatic illustration;

FIG. 2 shows the lifter of FIG. 1 in a coupling position of the springarms;

FIG. 3 shows the lifter of FIG. 1 in the middle shed position, in amodified diagrammatic illustration;

FIG. 4 shows the lifter of FIG. 1 in the upper shed position, in amodified diagrammatic illustration;

FIG. 5 shows a modified lifter in the middle shed position, with anactuator designed as a piezoelectric element, in a modified diagrammaticillustration;

FIG. 6 shows a modified lifter on a machine stand in a diagrammaticillustration; and

FIG. 7 shows the switch member of FIG. 6 as a detail and in the sectionVII—VII of FIG. 6.

Ways of implementing the invention and commercial practicability

FIGS. 1 to 4 illustrate in a diagrammatic illustration a lifter 2 of ajacquard machine in various working positions, parts not essential forthe essence of the invention being omitted.

The lifter 2 has a displacement member 4, to which is connected at thelower end, via a loop 6, a heddle 8 which is prestressed against amachine stand 12 via a spring 10. By means of this prestress, thedisplacement member 4 is prestressed, in the lower shed position T,against a lower stop 14 on the machine stand. An eye 16 arranged in theheddle 8 serves for the take-up of a warp thread 18, in order to movethe latter back and forth out of the lower shed position T of FIG. 1through the middle shed position M of FIG. 3 into the upper shedposition H of FIG. 4 and thereby form a shed 24. The displacement member4 is held displaceably in the longitudinal direction via a profiled backpart 26 by means of a guide of the machine stand, said guide not beingillustrated in any more detail here.

The displacement member 4 contains two upward-pointing spring arms 28 aand 28 b which contain mechanical coupling means 30 in the form ofoutward-pointing hooks 32 which can in each case be coupled to ascendingand descending lifting knives 34 a and 34 b having corresponding drivers36 for the hooks 32. The spring arms 28 a and 28 b assume a basicposition, shown in FIG. 1, in which they are free of the lifting knives34 a , 34 b, that is to say cannot be coupled without control. Thedisplacement member 4 contains a resilient switch member 38 which can beactuated by means of a fixed actuator 40, in order to move the springarms 28 a and 28 b out of the basic position of FIG. 1 into the couplingposition of FIG. 2 for the lifting knives 34 a and 34 b. For thispurpose, the switch member contains a spreading wedge 42 which isarranged at the front end of a spring tongue 44 of the displacementmember 4. The actuator 40 is, for example, part of an electromagnet 46connected via a line 48 to an electronic control device 50 whichtransmits a pattern-related control signal to the actuator. Thedisplacement member 4 further contains a catch 52, in which the actuator40 catches when the lifter 2 together with the displacement member 4 isin the upper shed position H, as may be gathered from FIG. 4.

The lifter functions as follows.

FIG. 1 shows the lifter 2 in the lower shed position T, in which itstands at the lower stop 14. The spring arms 28 a, 28 b are likewise inthe basic position, since the switch member 38 is likewise in the basicposition. In this basic position, it is not possible for the spring arms28 a, 28 b to cooperate with the lifting knives 34 a, 34 b. When theswitch member 38 is activated by the control device 50 via the actuator40 by means of a control signal, the spreading wedge 42 of the switchmember 38 is driven between the spring arms 28 a, 28 b, with the resultthat these come with their coupling means 30 into the displacement pathof the lifting knives 34 a, 34 b. The lifter is then driven into theupper shed position by one of the lifting knives 34 a or 34 b which isjust in the lower shed position. There is no conflict between thelifting knives 34 a, 34 b, since, when one lifting knife 34 a is in thelower shed position and therefore cooperates with a spring arm, theother lifting knife is in the upper shed position, where it does notcooperate with the associated spring arm. After a spring arm is coupledto a lifting knife, the switch member 38 is drawn back. By virtue of thehook shape of the coupling means, the corresponding spring arm remainshooked together with the corresponding lifting knife, in order to raisethe lifter. The free spring arm returns to the basic position, as may begathered from FIG. 3.

FIG. 4 shows an important state of the lifting knife in its highestposition, the lifter being just above the upper shed position. If thelifter is to remain selectively in the upper shed position, the actuator40 is reactivated and interlocks with the catch 52, with the result thatthe lifter can no longer follow the lifting knife during the return ofthe latter. The entire mechanism has a small overmovement at the uppershed position, said overmovement facilitating, on the one hand, acoupling and uncoupling of the spring arms of the lifting knives and, onthe other hand, the actuation of the actuator 40, since the elements tobe switched are relieved of the tensile forces at the heddle. To lowerthe lifter out of the upper shed position, one of the lifting knives cangrasp the hook 32 of a spring arm, since, by virtue of an upper fixedspreading member with run-on surfaces 53, the spring arms are deflectedinto the displacement path of the lifting knives 34 a, 34 b. The liftingknife then raises the displacement member 4 and consequently the lifter2 according to the small overmovement and thus makes it easier for theactuator 40 to be disengaged, whereupon the lifter can follow thedownward movement of the lifting knife. When the lifter 2 stands at thelower stop, the lifting knives 34 a and 34 b likewise execute a smalldownward overmovement in the lower shed position, with the result thatthe uncoupling of the spring arms from the lifting knives isfacilitated, so that the spring arms can spring back into the basicposition. It is thereby possible for a lifting knife to be raised out ofthe lower shed position, without cooperation with a spring arm andwithout the lifter being raised. It is also possible to control theswitch member in such a way that the spring arm either dwells in thecoupled position or is moved into this position before the lifting knifehas passed the coupling level, so that the lifter is raised out of thelower shed position during the next shot of a weft thread through theshed.

The known double-lift technique is therefore possible in a simple way bymeans of the present design of the jacquard machine.

FIG. 5 shows the lifter 2 of FIGS. 1 to 4, which is guided with its backpart 26 in a guide 54 fastened to the machine stand 12. Moreover, in theexample of FIG. 5, the actuator 40 a is not designed as part of anelectromagnet, but as part of a piezoelectric element 56 which islikewise fastened fixedly to the machine stand 12.

FIGS. 6 and 7 show a modified lifter 2 a of FIG. 5, the guide 54 beingarranged on a plate 58 of the machine stand 12. In this case, thearrangement is such that the guide 54 of a lifter also serves at thesame time as a holding device for the piezoelectric element 56 of theadjacent lifter. The lifter 2 a or the displacement member 4 a of thelifter of FIG. 6 has a plurality of catches 60, 60 a, 60 b which aredistributed over the height and on which the actuator 40 a can catch.The catches 60, 60 a, 60 b arranged at different heights allow acorrespondingly differentiated opening of the shed over acorrespondingly different shed height, since the shed height is equal tothe distance which corresponds to the raising of the lifter out of thelower shed position of FIG. 1 into the upper shed position of FIG. 4. Adifferent shed height also makes it necessary, of course, for thelifting knives to execute a correspondingly adapted lift. The shedheight may, under certain circumstances, also be increased downward bythe lower stop being downwardly adjustable. Here, too, the lift of thelifting knives must be adapted to a changed position of the lower stop.

It may be gathered from FIG. 7 that the spreading wedge 42 of the switchmember 38 cooperates with correspondingly beveled switch surfaces 62 ofthe spin arms 28 a and 28 b.

List of reference symbols T Lower shed position M Middle shed position HUpper shed position 2 Lifter 2a Lifter 4 Displacement member 4aDisplacement member 6 Loop 8 Heddle 10 Spring 12 Machine stand 14 Lowerstop 16 Eye 18 Warp thread 24 Shed 26 Back part 28a Spring arm 28bSpring arm 30 Coupling means 32 Hook 34a Lifting knife 34b Lifting knife36 Driver 38 Switch member 40 Actuator 40a Actuator 42 Spreading wedge44 Spring tongue 46 Electromagnet 48 Line 50 Control device 52 Catch 53Run-on surfaces 54 Guide 56 Piezoelectric element 58 Plate 60 Catch 60aCatch 60b Catch 62 Switch surface

1. A jacquard machine comprising: an actuator; oppositely ascending anddescending lifting knives; and lifters which can be connected to threadsto be controlled and which can be coupled, corresponding to controlsignals from an electronic control device, in a form-fitting manner tosaid oppositely ascending and descending lifting knives, each lifterhaving a displacement member which can be connected to at least onethread to be controlled and which carries two spring arms which in thebasic position are free of the lifting knives by means of a switchmember capable of being actuated by said actuator, and in the upper shedposition the displacement member being interlockable by means of theactuator, wherein the switch member is arranged at the end of a springtongue oriented in the direction of displacement and fastened to thedisplacement member outside the spring arms, the actuator being arrangedlaterally outside the spring arms and so as to act transversely thereto.2. The jacquard machine as claimed in claim 1, including at least onerigid catch, with which the actuator cooperates directly, is arranged onthe displacement member for detention of the actuator in the upper shedposition.
 3. The jacquard machine as claimed in claim 1, wherein thedisplacement member has at least two catches arranged at differentheights.
 4. The jacquard machine as claimed in claim 1, wherein theactuator is part of an electromagnet.
 5. The jacquard machine as claimedin claim 1, wherein the actuator is part of a piezoelectric element. 6.The jacquard machine as claimed in claim 1, wherein the jacquard machinehas run-on surfaces which keep the spring arms spread in the couplingposition when in the upper shed position.
 7. The jacquard machine asclaimed in claim 1, wherein the lifter is assigned a settable stopdetermining the lower shed position.
 8. The jacquard machine as claimedin claim 1, wherein the displacement member has, on the side facing awayfrom the actuator, a back part which is equipped with a guide profileand which is mounted displaceably in a guide in a machine stand.
 9. Thejacquard machine as claimed in claim 1, wherein the lifting knives aredesigned to execute an overmovement in at least one of the upper shedposition and the lower shed position.
 10. The jacquard machine asclaimed in claim 2, wherein the actuator is part of an electromagnet.11. The jacquard machine as claimed in claim 2, wherein the actuator ispart of a piezoelectric element.
 12. The jacquard machine as claimed inclaim 2, wherein the jacquard machine has run-on surfaces which keep thespring arms spread in the coupling position when the lifter is in theupper shed position.
 13. The jacquard machine as claimed in claim 2,wherein the lifter is assigned a settable stop determining the lowershed position.
 14. The jacquard machine as claimed in claim 2, whereinthe displacement member has a side facing away from the actuator havinga back part which is equipped with a guide profile and which isdisplaceably mounted in a guide in a machine stand.
 15. The jacquardmachine as claimed in claim 2, wherein the lifting knives are designedto execute an overmovement in one of the upper shed position and thelower shed position.
 16. The jacquard machine as claimed in claim 2,wherein the actuator is part of an electromagnet.
 17. The jacquardmachine as claimed in claim 3, wherein the actuator is part of apiezoelectric element.
 18. The jacquard machine as claimed in claim 3,wherein the jacquard machine has run-on surfaces which keep the springarms spread in the coupling position when the lifter is in the uppershed position.
 19. The jacquard machine as claimed in claim 3, whereinthe lifter is assigned a settable stop determining the lower shedposition.
 20. The jacquard machine as claimed in claim 3, wherein thedisplacement member has a side facing away from the actuator having aback part which is equipped with a guide profile and which isdisplaceably mounted in a guide in a machine stand.
 21. The jacquardmachine as claimed in claim 3, wherein the lifting knives are designedto execute an overmovement in one of the upper shed position and thelower shed position.